If implemented optimally, recent World Health Organization recommendations can reduce the risk of mother- to-child HIV transmission (MTCT) to less than 5% in breastfeeding populations and less than 2% in non- breastfeeding populations. Successful implementation of prevention of mother-to-child HIV transmission (PMTCT) interventions that maximize maternal health and infant HIV-free survival requires high levels (>95%) of uptake and adherence to a continuum of services also referred to as the PMTCT cascade. Interventions that substantially improve uptake and adherence to the PMTCT cascade are critical for reaching the global goal of virtual elimination of MTCT by 2015. In the past decade, conditional cash transfers (CCTs) have become a widely-used intervention for achieving behavior change, but they have not been applied to the PMTCT setting and little is known about the mechanisms through which CCTs facilitate the adoption of health promoting behaviors. The aims of this study are 1) to test whether small, increasing cash payments to HIV- infected pregnant women, on the condition that they attend all scheduled clinic visits and uptake of services, will increase the proportion of women who receive the most effective antiretroviral (ARV) regimen they are eligible for and deliver at an affiliated maternity, and 2) identify: a) factors that facilitate or inhibit uptake and adherence to PMTCT services, including HIV-infected pregnant women's perception of MTCT risk and the severity of the potential impact of HIV infection on their infants' health; and b) the extent to which identified barriers to PMTCT uptake and adherence were mitigated by the CCT program. The study will be conducted in our PEPFAR/CDC-funded HIV prevention, care, and treatment program in Kinshasa, Democratic Republic of Congo (DRC) which include for PMTCT, a network of 44 maternities, and serving over 50,000 pregnant women. At their first visit between 28 and 32 weeks of gestation, 600, newly diagnosed, HIV-positive pregnant women will be randomized to: 1) the standard of care, or 2) the standard of care plus increasing cash payments, starting at $5 and increasing by $1 each month, trough six-week postpartum. There will be a reset contingency wherein the escalating value of the incentive goes back to its original value ($5) should the mother fail to complete any of the actions required at a specific visit including: attending the monthly scheduled clinic visits, providing a blood sample for CD4 count, uptake of HIV care and treatment if referred, and adhere to prescribed antiretroviral drugs. The study will be conducted in partnership with the DRC Ministry of Health through the national AIDS control program (PNLS), the Catholic Medical Board (BDOM), the DRC Salvation Army, and the Kinshasa School of Public Health. In the DRC, our results will inform the ongoing effort by PEPFAR and the DRC government towards the goal of virtual elimination of pediatric HIV by 2015. If shown to be effective, the contingency management scheme we propose can be easily integrated into other PMTCT programs throughout low and middle income countries. PUBLIC HEALTH RELEVANCE: To inform the ongoing debate over how to ensure that pregnant HIV-infected women and their infants receive vital services for the prevention of mother-to-child HIV transmission (PMTCT), we will test the effectiveness of an escalating scheme of small, conditional cash transfers (CCTs) to increase patient retention and service uptake. Additionally, we will examine how HIV-infected women process information they receive during antenatal care visits and how they perceive vertical transmission risk, in order to better understand how CCTs affect adherence to care. If shown to be effective, the low-cost CCTs we propose can be easily integrated in PMTCT programs throughout other low- and middle-income countries.